1. Field of the Invention
The present invention relates to a zoom lens system.
2. Description of Related Art
Japanese Unexamined Patent Publication Nos. 2011-186417, 2011-232543 and 2011-252962 each disclose a zoom lens system configured of a positive first lens group, a negative second lens group, a positive third lens group, a negative fourth lens group, and a positive fifth lens group, in that order from the object side.
The zoom lens system in Japanese Unexamined Patent Publication No. 2011-186417 has a zoom ratio of 16:1 through 18:1, which is either a zoom ratio that is not sufficiently high or the telephoto ratio (the ratio of the focal length at the long focal length extremity to the entire length of the zoom lens system at the long focal length extremity) is approximately 1.0, so that miniaturization of the zoom lens system (reduction of the overall length of the zoom lens system in the optical axis direction) is insufficient. Furthermore, the zoom lens system disclosed in Japanese Unexamined Patent Publication No. 2011-232543 has a zoom ratio of a range of 10:1 through 15:1 and the zoom lens system disclosed in Japanese Unexamined Patent Publication No. 2011-252962 has a zoom ratio of a range of 15:1 through 20:1, which are both insufficient for achieving a high zoom ratio.